Submission #1184340

#	Time	Username	Problem	Language	Result	Execution time	Memory
1184340		sasde	Ball Machine (BOI13_ballmachine)	C++20	45.77 / 100	1097 ms	28476 KiB

ballmachine

#include<bits/stdc++.h>
#define str string
#define task "strdel"
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define se second
#define fi first
#define ffi fi.fi
#define sfi se.fi
#define sse se.se
#define fse fi.se
#define lt(i, c, d) for(int i = c; i <= d; ++i)
#define fl(i, c, d) for(int i = d; i >= c; --i)
#define pb push_back
#define emb emplace_back
#define emf emplace_front
#define em emplace
using namespace std;
const int N=1e5+5,lg=20,mod=1e9+7;
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int Rand(int u,int v){
 return u+rd()%(v-u+1);
}
int n,q,goc,sz[N],h[N],up[N][lg+5],minn[N];
int st[N*4],lazy[N*4];
vector<int>a[N];
void down(int id){
    st[id<<1]+=lazy[id];
    st[id<<1|1]+=lazy[id];
    lazy[id<<1|1]+=lazy[id];
    lazy[id<<1]+=lazy[id];
    lazy[id]=0;
} 
int walk_up(int id,int r,int l,int u,int v,int val)
    {
        if(r<u||l>v||st[id]>val)
            return -1;
        if(l==r)
        {
            return r;
        }
        down(id);
        int mid=(l+r)>>1;
        int res=walk_up(id<<1|1,mid+1,l,u,v,val);
        if (res==-1)
            res=walk_up(id<<1,r,mid,u,v,val);
        return res;
    }
int walk_down(int id,int l,int r,int u,int v,int val)
    {
        if(r<u||l>v||st[id]>val)
            return -1;
        if(l==r)
        {
            return r;
        }
        down(id);
        int mid=(l+r)>>1;
        int res=walk_down(id<<1,r,mid,u,v,val);
        if (res==-1)
            res=walk_down(id<<1|1,mid+1,l,u,v,val);
        return res;
}
void update(int id,int r,int l,int u,int v,int val){
    if(r>v||l<u)return;
    if(r>=u&l<=v){
        st[id]+=val;
        lazy[id]+=val;
        return;
    }
    int mid=(r+l)>>1;
    down(id);
    update(id<<1,r,mid,u,v,val);
    update(id<<1|1,mid+1,l,u,v,val);
    st[id]=st[id<<1]+st[id<<1|1];
}
int get(int id,int r,int l,int u,int v){
    if(r>v||l<u)return 0;
    if(r>=u&&l<=v)return st[id];
    int mid=(r+l)>>1;
    down(id);

    return get(id<<1,r,mid,u,v)+get(id<<1|1,mid+1,l,u,v);
}
void dfs(int u){
  minn[u]=u;sz[u]=1;
  for(int v:a[u]){
    h[v]=h[u]+1;
    up[v][0]=u;
    dfs(v);
    sz[u]+=sz[v];
    minn[u]=min(minn[u],minn[v]);
  }

}
int arr[N],curid[N],curhead[N],pos[N],curc=1,curpos=1;
void hld(int u,int cha){
    // cout <<u<<" ";
    if(!curhead[curc]){
        curhead[curc]=u;
    }
    curid[u]=curc;
    pos[u]=curpos;
    arr[curpos]=u;
    curpos++;
    int nxt=0;
    for(int v:a[u]){
        if(v!=cha){
            if(sz[nxt]<sz[v])nxt=v;
        }
    }
    if(nxt)hld(nxt,u);
    for(int v:a[u]){
 
    if(v!=nxt&&v!=cha){
            ++curc;
            hld(v,u);}
    }
}
int lca(int u,int v){
    while(curid[u]!=curid[v]){
        if(curid[u]>curid[v]){
            u=up[curhead[curid[u]]][0];
        }
        else{
            v=up[curhead[curid[v]]][0];
        }
 
    }
  // cout <<u<<" "<<v<<'\n';
    if(h[u]<h[v])return u;
    return v;
}
long long query(int u,int v){
    long long ans=0,l=lca(u,v);
    while(curid[u]!=curid[l]){
        ans+=get(1,1,n,pos[curhead[curid[u]]],pos[u]);
             u=up[curhead[curid[u]]][0];
    }
    while(curid[v]!=curid[l]){
        ans+=get(1,1,n,pos[curhead[curid[v]]],pos[v]);
             v=up[curhead[curid[v]]][0];
    }
    if(h[u]<h[v]){
             ans+=get(1,1,n,pos[u],pos[v]);
    }
    else  ans+=get(1,1,n,pos[v],pos[u]);
        return ans;
}
int sl,zz;
void dfs1(int u){
  for(int v:a[u]){
    dfs1(v);
  }
  if(sl>0){
    zz=u;
    update(1,1,n,pos[u],pos[u],1);
  }
    sl--;
}
void giai1(int x){
  sl=x;
  dfs1(goc);
  // cout <<query(1,7);
  cout <<zz<<'\n';
}
int laycha(int x,int u){
for(int j=0;j<=lg;++j){
  if(u&(1<<j)){
    x=up[x][j];
  }
}
return x;
}
void giai2(int x){
  int l=1,r=h[x],res=0;
  while(l<=r){
    int mid=(r+l)>>1;
    int u=laycha(x,mid);
    int sum=query(u,x);
    if(sum!=h[x]-h[u]+1){
      r=mid-1;
    }
    else{
      l=mid+1;
      res=mid;
    }
  }
  int 
  u=laycha(x,res);
  // cout <<u<<" "<<res;
  update(1,1,n,pos[u],pos[u],-1);
  cout <<res<<'\n';
}
void solve(){
    cin >> n >> q;
    for(int i=1;i<=n;++i){
        int u;
        cin >> u;
        if(u==0)goc=i;
        else a[u].emb(i);
    }
    dfs(goc);
    hld(goc,-1);
    for(int j=1;j<=lg;++j)
    for(int i=1;i<=n;++i)up[i][j]=up[up[i][j-1]][j-1];
    for(int i=1;i<=n;++i){
      sort(a[i].begin(),a[i].end(),[](const int &x,const int &y){
        return minn[x]<minn[y];
      });
    }
    while(q--){
      int t,u;
      cin >> t >> u;
      if(t==1)giai1(u);
      else giai2(u);
    }
}
main()
{
  srand(time(0));
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    if(fopen(task".inp","r")){
      freopen(task".inp","r",stdin);
      freopen(task".out","w",stdout);
    }
    int t=1;
 //   cin >> t;
while(t--){
    solve();
}

}

Compilation message (stderr)

ballmachine.cpp:220:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  220 | main()
      | ^~~~
ballmachine.cpp: In function 'int main()':
ballmachine.cpp:227:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  227 |       freopen(task".inp","r",stdin);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
ballmachine.cpp:228:14: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  228 |       freopen(task".out","w",stdout);
      |       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5.7692 / 25
• Subtask 2: 0 / 30
• Subtask 3: 40 / 40
• Subtask 4: 0 / 5